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Microcontrollers and DSPs Will They Converge?
Author: Bill Giovino
Executive Editor, Microcontroller.com
President, CPU Technologies of Boston
The two divergent paths of Microcontroller and DSP may cross occasionally with each
performing both tasks. Barriers to entry depend on peripherals, filling the data pipe, and
quality of development tools. Designers of today's emerging systems that require both
real-time control as well as analog signal processing are looking for ways to reduce cost
and speed development time in a market that has become increasingly competitive. Both
technical and personal considerations rule. For a microcontroller engineer to consider a
DSP or for a DSP engineer to use a microcontroller three strict criteria must be met:
price/performance, peripheral set, and development tool quality. The absolute
convergence of these two architectures are being met by MSPs, which are a joining of
the most advanced features of both, as well as the fastest clock rates in the embedded
Intel developed the 4004 microcomputer chip¹ in 1971 for the Busicom desktop
calculator (remember when a calculator took up a desktop?). It sold for $200, and ran at
92.5KHz internally. Intel's initial strategy was to use this device to sell more memory
chips. The 4004 was an unexpected hit and was quickly followed by a flurry of similarly
enhanced devices from Intel, Motorola, Zilog, and Texas Instruments. Important
features in the later devices were features like on-chip memory, I/O ports, and hardware
peripherals, enabling these devices to economize PC board space in control-oriented
In the past fifteen years, digital signal processors (DSP) have been in a specialized
segment of the embedded development marketplace, which is dominated by 8-bit and
16-bit microcontrollers. DSPs were initially used in highly specialized segments where
precision processing of analog signals could not be accomplished effectively using
conventional analog circuit components. In 1982, Texas Instruments proved that this
segment existed with the TMS32010 DSP by combining specialized hardware for
accelerating multiplication with a Harvard (dual bus) memory architecture, introducing
architectural enhancements that would be found on later digital signal processors.
A piece of trivia - the official part number for the Intel Pentium is 4004A.